Air Filter

ABSTRACT

An air filter including two opposing open ends, and a filter area circumferentially enclosing a cavity in between. The first open end frictionally and sealingly engages the filter housing including an air port, while the second end engages the housing to close the second end from passage of air. The filter area may be reinforced to provide a durable, reusable filter. The filter material may be selected to provide depth loading and increase the particulate capacity of the filter.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims priority to U.S. Provisional ApplicationNo. 61/794,421, filed Mar. 15, 2013 and titled “Air Filter,” which isincorporated in its entirety herein.

FIELD OF THE INVENTION

The field of the invention is generally related to filter devices. Morespecifically, the field of the invention is related to vehicle airfilters.

BACKGROUND

An air filter designed to remove particulate is generally a devicecomposed of fibrous materials. These fibrous materials may remove solidparticulates such as dust, pollen, mold, and bacteria from the air. Airfilters are used in applications where air quality is important, notablyin building ventilation systems and in engines.

Air filters may be used in automobiles, trucks, tractors, locomotivesand other vehicles that use internal combustion engines. Air filters maybe used with gasoline engines, diesel engines, or other engines that runon fossil fuels or other combustible substances. Air filters may be usedwith engines in which combustion is intermittent, such as four-strokeand two-stroke piston engines, as well as other types of engines thattake in air so that a combustible substance may be burned. For example,air filters may be used with some gas turbines. Filters may also be usedwith air compressors or in other devices that take in air.

Filters may be made from pleated paper, foam, cotton, spun fiberglass,or other known filter materials. Generally the air intakes of internalcombustion engines and compressors tend to use either: paper, foam, orcotton filters. Some filters use an oil bath. Air filters for internalcombustion engines prevent abrasive particulate matter from entering theengine's cylinders, where it would cause mechanical wear and oilcontamination. In many fuel injected engines, a flat panel pleated paperfilter element may be used. This filter is usually placed inside aplastic box connected to the throttle body with ductwork. Vehicles thatuse carburetors or throttle body fuel injection typically use acylindrical air filter positioned above the carburetor or throttle body.

Air filters may also be used to filter cabin air, for example, airwithin a vehicle such as a car, truck, airplane, bus, train, tractor,etc. These air filters may typically be a pleated-paper filter in whichoutside-air is passed through the filters before entering the vehicle'spassenger compartment. Some of these filters are rectangular and similarin shape to the combustion air filter.

SUMMARY OF THE INVENTION

The present invention provides an air filter. Additionally, the presentinvention may provide an air filter system and methods of using the airfilter.

Embodiments as described herein may include an air filter with a firstend, a second end, and a filter material between the first end and asecond end. The first and second end may be open, while the filtermaterial may fully circumscribe and surround the respective ends, thuscreating a filter having a cylindrical outer profile and a passagelongitudinally therethrough. One end may be configured to accept an airflow conduit, thus forcing air into or removing air from the interiorpassage. The opposing end may be configured to sealingly engage a filterhousing, such that air is not permitted to pass therethrough, but isinstead forced through the filter material. The ends are shaped suchthat they create the requisite sealing engagement with the respectivesurfaces without requiring additional sealing gaskets, or components.The ends are configured to conform and/or deform to the surfaces suchthat a frictional, sealing engagement is created. Therefore, theengagement both maintains the filter in the desired location as well asprovides the necessary connections to direct the air through the filtersystem. The ends may also configured to maintain the sealing engagementduring deformation of the ends through thermal expansion andcontraction.

To this end, in an exemplary embodiment, an air filter, comprising: afirst end cap at a first terminal end of the air filter, the first endcap having a first opening; a second end cap at a second terminal end ofthe air filter opposite the first terminal end, the second end caphaving a second opening; and a filter media coupled to and sealedbetween the first end and the second end to circumferentially surroundan interior cavity.

In an exemplary embodiment, comprising a rim defining the first openingand extending longitudinally past an exterior terminal end of the firstend cap.

In an exemplary embodiment, wherein an interior surface of the rimdefining the first opening is tapered such that an interior diameter ata terminal edge of the end cap away from the filter media is greaterthan an interior diameter along the interior surface away from theterminal edge.

In an exemplary embodiment, wherein the tapered interior surface isaccurate.

In an exemplary embodiment, further comprising a flangecircumferentially surrounding a longitudinal portion of the rimextending longitudinally past a terminal end of an exterior perimeter ofthe first end cap.

In an exemplary embodiment, wherein the flange projects radiallyinwardly.

In an exemplary embodiment, wherein the second end cap comprises aninterior rim defining the second opening and projecting longitudinallyoutwardly from an terminal end of a portion of the second end cap.

In an exemplary embodiment, wherein the second end cap comprises anexterior rim defining an exterior perimeter of the second end projectinglongitudinally outward from the terminal end of the portion of thesecond end cap, such that a radial gap separates the interior rim fromthe exterior rim.

In an exemplary embodiment, wherein an interior surface of the interiorrim comprises a circumferential ridge around the first opening.

In an exemplary embodiment, wherein a material of the first end isconfigured to deform when mated with a filter housing.

In an exemplary embodiment, wherein a material of the second end isconfigured to deform when mated with a filter housing.

Various objects, features, aspects and advantages of the presentinvention will become more apparent from the following detaileddescription of preferred embodiments of the invention, along with theaccompanying drawings in which like numerals represent like components.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 illustrates a perspective view of an exemplary air filteraccording to embodiments described herein.

FIG. 2 illustrates a perspective view of a first end of the air filteraccording to embodiments described herein.

FIG. 3A illustrates an end plan view of the second end according toembodiments described herein, and FIG. 3B illustrates a side view of thesecond end of FIG. 3A.

FIG. 4 illustrates a cross-sectional cut away side view according toembodiments described herein.

FIG. 5 illustrates an exemplary embodiment of the air filter medium.

FIG. 6 illustrates a cross-sectional view of an exemplary air filterwithin a housing according to embodiments described herein.

FIGS. 7A and 7B illustrate cross-sectional, blown up terminal ends ofFIG. 6.

It will be understood that the terms “top,” “side,” and “bottom” used todescribe FIGS. 1-6 are intended to provide a frame of reference forpurposes of describing embodiments of the air filter. The actualorientation of the air filter in use and the direction of air flow mayvary.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In the following description of preferred embodiments, reference is madeto the accompanying drawings which form a part hereof, and in which itis shown by way of illustration of specific embodiments in which theinvention can be practiced. It is to be understood that otherembodiments can be used and structural changes can be made withoutdeparting from the scope of the embodiments of this invention.

Although embodiments of the invention may be described and illustratedherein in terms of a single example air filter, it should be understoodthat embodiments of this invention are not limited to the exact shapeillustrated, but rather, include a wide variety of generally cylindricalshapes, generally circular, oval, round, curved, or other closedperimeter shape, that provides a relatively large surface area in agiven volume of the filter.

According to embodiments as described herein, an exemplary air filter 2has a filter area 4, a first end 6, and a second end 8. As shown in FIG.1, the filter area 4 is composed of a filter material 12 thatcircumferentially surrounds an open interior cavity 10 such that thefilter material 12 creates an exterior perimeter of at least a portionof the cavity. The exterior shape may be generally circular, oval,conical, or otherwise shaped to improve the surface area available forair flow passage for a given volume. The shape may be consistent along alongitudinal length or may vary along the length. For example, the outerprofile may taper from one end to the other. The length of the filtermaterial 12 in the circumferential direction may be longer than thecircular circumference of the filter generally, such that the surfacearea of the filter material is greater than the profile surface area ofthe filter.

The filter area 4 provides an area to pass an air stream and trapparticulates and other contaminates. The filter material may be paper,foam, cotton, spun fiberglass, or other known filter materials, woven ornon-woven material, synthetic or natural, or any combination thereof.The filter material may be pleated or otherwise shaped or contoured toincrease a surface area for passing the air stream to be cleaned.

In an exemplary embodiment, the filter material 12 includes acombination of materials to create a hybrid filter medium. The hybridair filtration medium is a non-woven synthetic material designed to beused dry with no oil required. Many non-woven mediums have atwo-dimensional or “flat” surface. The hybrid filter media according toembodiments described herein comprised lofted non-woven syntheticfibers. This three dimensional platform adds a depth loading feature.Depth loading gives an air filter high airflow with low restrictionwhile providing large dust holding capacities. The hybrid air filtrationmedium permits a low restriction air filter that could be cleaned almostanywhere and in anyway

As shown in FIG. 5, the hybrid filter medium includes a thick loftednon-woven synthetic media. The material is pleated to increase thesurface area available for passing contaminated air. A first layer 14may be configured on the side directed toward the incoming air stream tobe cleaned (i.e. the dirty incoming air flow), while a second materiallayer 15 may be positioned behind the first material layer toward theexit side of the air flow (i.e. the cleaned outgoing air flow). A thirdlayer 16 may be on the air exit side of the second layer 15. Thematerial of each of the layers may include a non-woven syntheticmaterial to promote depth loading of the deposited particulate matter,The first layer 14 may then be lofted to help enhance the depth loadingof the particulate material. The lofting may be achieved throughpricking, pulling, or otherwise separating fibers of the first layer.The first layer 14 may be very course to capture larger particulatematerial. As the air flow penetrates deeper into the media, the materialmay become increasingly finer to capture increasingly smallerparticulate. Therefore, for example, the material of the third layer 16may comprise finer separation distances between fibers than that of thefirst layer 14. The coarseness of the material may be constant for agiven layer, or may gradually increase or decrease across the one ormore layers.

These commercial grade air filters built from a new hybrid filter mediumincorporates some of the best characteristics of both cotton andsynthetic non-woven technologies. They do not require any oil treatmentand use a 3-D lofted filter surface to help reduce air filterrestriction while increasing dirt capacity. Less restriction means morepower and better engine efficiency. As air filter restriction goes up,an engine needs to expend energy “pulling” air through the filter, Thisis wasted energy that is no longer available for power at the wheels,Another air flow benefit is achieve each time the air filter is washed,restriction is reduced whereas disposable air filters slowly increase inrestriction throughout their service life.

Additional reinforcement may be included to provide additional strengthand durability for reusable applications. Therefore, the filter may becleaned and reused instead of being discarded after each application.For example, the air filter media 12 may be positioned between one ormore layers of a reinforcing layer. As shown, a wire screen 18 may beused on an outer and inner surface of the filter media. The wire screenmay be a powder-coated aluminum screen wire that is co-pleated alongwith the filter medium to reinforce the media material. Additional oralternate reinforcement may be provided, for example, by an exteriorand/or interior cage 20 surrounding the filter media. For example, acriss-crossed steel cage may provide additional reinforcement for thefilter media on an interior and exterior surface of the filter. Thereinforced medium surrounded by a powder-coated steel cage may withstandthe extreme temperatures and pressures that can be present in largeturbo diesel applications. The strong and robust reinforced medium maypermit the air filter to be used multiple times. For example, the airfilter according to embodiments described herein may be used in place ofup to 10 or more disposable air filters.

The air filter medium may be selected or configured to providereversible air flow or unidirectional air flow through the filter. In anexemplary embodiment, the first layer 14 is positioned on an interiorside of another third material layer 16 so that the dirty air entersfrom an end and fills the interior cavity, travels across the filtermaterial from an interior surface to an exterior surface and away fromthe filter. The material configuration may be reversed for reverse flow,or may be symmetric or mirrored to provide reversible air flow throughthe filter.

The reinforced medium 12 including an interior and exterior steel cage20 is then held between end caps 22 and 24. The end caps may be eitherrubber or plastic or other resilient or deformable material that issufficiently strong to support the filter. For example, one or both ofthe end caps may be molded urethane, foam urethane, or an polyurethaneelastomer, and/or may include a steel, or aluminum infrastructure. Inthe exemplary embodiment shown, a elastomer molded polyurethane is usedto provide an additional hardness and robust exterior seat for thefilter medium. For reusable filters, the molded elastomer is preferableover foam to reduce degradation during the cleaning process.

The first end cap 22 and/or second end cap 24 may be configured to matewith a corresponding surface of an air flow housing to secure the filterrelative to the housing. As the air is directed through filter area 4,to increase air flow and improve performance, the space around thefilter to the housing should be maintained. The filter is thereforepositioned within the housing to maximize the airflow and the end capsare configured to retain the filter in the desired location.

The first end cap 22 is configured to frictionally engage an insertedair conduit to seal the conduit to the filter. The frictional engagementmay be achieved through the deformation of a surface of the first endcap. The material of the end cap may be sufficiently strong to supportthe filter and generally maintain a given configuration, but may besufficiently pliable that an surface may deform to conform to aninserted conduit. The end cap may therefore include a flangecircumscribing an opening of the first end cap. An interior surface ofthe flange may radially expand to accommodate an inserted air flowconduit.

An exemplary first end cap 22, as illustrated in FIG. 2, includes alarge circular opening 28 in its center. The opening is defined by acircular ridge or rim 30 projecting generally longitudinally away fromthe interior cavity 10 of the filter. The rim defines an opening to theinterior of the filter. The interior surface of the rim 30 may bereverse tapered such that it is widest at an exterior edge andcontinuously decreases in diameter toward an interior of the filter. Thefunnel or conical shaped interior surface can be used to direct incomingair flow from an attached conduit. The reverse taper may be gradualalong a length. The taper may be linear or arcuate. As shown, thereduced diameter transition is convex arcuate, such that the taper isgreatest near an outer edge of the projection and becomes increasinglydiminished as the surface approaches the interior portion of the filterarea. Thus, the opening slopes or tapers such that it narrows by agreater extent toward an exterior edge and continues to taper as itapproaches the open interior of the filter media pack, but at agradually decreasing amount. The first end cap opening provides accessto the central open interior of the filter, and can be installed over anair inlet tube of a filter housing to allow air to flow into theinterior of the filter. The exterior surface of the rim 30 is generallycircular cylindrical, such that the outer profile of the rim 30 isgenerally constant along its longitudinal length.

In an exemplary embodiment, to accommodate an inserted surfaceassociated with the filter housing, a recess 32 may circumferentiallysurround a base of the projection 30. The recess may be generallycircular and be directly adjacent the rim 30. The recess iscircumferentially defined on the interior side by the rim 30 and on anexterior side by a flange 34. The flange 34 may be shaped according tothe housing and may provide an abutment surface to further seal and/orsecure the filter to the housing. The flange 34 may longitudinally endsfrom an exterior terminal end of the end cap 22 and slightly radiallyinward. The transverse width of the flange may taper to a minimumdiameter at the terminal end. The radially inward orientation of flange34 may provide an inward frictional engagement with an insertedcorresponding mating surface of the filter housing 26.

In an exemplary embodiment, the end caps are configured to frictionallyengage an air filter housing 26. The engagement is also configured toseal the filter to the housing and prevent air from bypassing the filterarea 4. The engagement may be ribbed, threaded, or otherwise provide africtional, sealing engagement between the tube and filter. In anexemplary embodiment, the contour of the terminal end of the first endcap 22 may be configured to accommodate and mate with a correspondingcontour of a filter housing. The end cap 22 radially seals the filter toa conduit of the air filter housing. The filter, such as rim 30 orflange 34 may deform to seal the filter housing against correspondingmating surfaces 36 and/or 38. The frictional engagement may be createdthrough the compression or deformation of the material' of the end capto conform to a surface of the inserted filter housing.

A rim 30, recess 32, and flange 34 may be integrally formed and moldedto the filter medium to securely retain the medium in place. The rim 30or flange 34 or other surface of the end cap 22 may be used as a gasketto seal the filter to the housing and/or pipe. Therefore, additionalcomponents that may wear out or require replacement may be reduced oreliminated.

In an exemplary embodiment, the smallest diameter portion of theinterior profile of the first end cap 22 is continuous with the interiorof the filter area or interior cage 20, such that the diameter of theopening is the same as the diameter of the filter area. In an alternateembodiment, the diameter of the opening may be less than a diameter ofthe filter area. In either embodiment, the opening may comprise a ledgearound the edge of the opening, such that the inside surface rises toform a narrow circular ridge that projects inwardly into the interior ofthe filter in the direction of the second end cap. The ridge of theinside surface may be used to prevent moisture from leaving the insidesurface through the opening up to the height of the ridge. The ridge maybe an projection into the interior opening. The ridge may be along onlya portion of the filter or fully surround the opening. The ridge mayproject toward the opposing end, directly inward, or outward.

A second open end cap 24 is provided opposite the first end cap 22. Theend cap forms a generally planar end. The planar end includes a flangedrim circumscribing the perimeter of the end. The flanged rim extendsfrom the perimeter of the planar end radially outward and longitudinallyaway from the filter body, thus forming a generally frusto-conical rimaround the circumference of the second end. A second generally annularrim 42 may circumscribe and define an interior opening through thesecond end. The interior rim 42 may generally project longitudinally toform a generally cylindrical projection. The interior surface 44 of theopening of the interior rim 42 may be reverse tapered so that along theprojection the diameter increases from the opening through the planarend to a larger diameter at a terminal end of the rim. The taper may belinear or may be generally arcuate so that the taper is greater along aportion, such as for example an outer portion of the rim. The planar endcap may include one or more recesses 46 between the inner and outerrims. The interior surface 44 of the interior rim 42 may also include aridge or projection 48 into the opening. This ridge 48 may be agenerally annular ring on the tapered interior surface of the inner rim.

The outside surface of the second end cap is shown in FIG. 3. The secondend cap also includes a circular opening in its center that is definedby a circular projection or ridge. The circular projection defining theopening also tapers from a larger diameter at a longitudinal outer edgeto a smaller diameter toward the center of the filter. The opening maybe generally the same size as the inner diameter of the filter region.Preferably, the inner diameter of the opening along its entire length issmaller than the inner diameter of the filter region. As shown, thesecond end cap opening is smaller than the first end cap opening. Thus,the opening slopes or reverse tapers such that it narrows as itapproaches the open interior of the filter media pack. There is also asmall circular indentation to form a stepped ridge along the interiorouter edge.

As can be seen in FIG. 3B, the outer rim of the end cap is formed by acircular projection or ridge that extends at an angle axially andradially outward from the filter region. The exterior outer profilealong the longitudinal length of the outer rim of the end cap isgenerally truncated conical. For example, the region of the outer rimwith the largest diameter is the region at the top of the circularprojection or terminal end of the filter/end cap. The diameter tapersinwardly from the region at the top of the circular projection towardthe filter media pack. Between the circular projection defining theopening and the outer rim of the second end cap is a relatively widecircular recess. The circular recess also includes two narrow circulartrenches in the floor of the circular recess. Any number of recesses maybe included, or may not be present at all.

The tapered interior surface of the first end cap can form a sealagainst a circular ridge on a cover of a filter housing. The filterhousing 26 comprises a contoured end that mates with the second end cap24. The filter housing 24 slopes outward to correspond and mate with theinterior surface 44 of interior rim 42. The housing may include anindentation to mate with the projection 48 or may deform the projectionsuch that the projection acts as a gasket in the seal between the filterand the housing. The interior rim 42 may deform in mating with thehousing to create an air tight frictional seal between the housing andfilter. The exterior rim 40 may similarly engage and or deform incontact with an interior surface of the housing to further seal andretain the filter in a desired configuration.

Thus, as seen in FIG. 6, when positioned in a filter housing 26, thefilter 2 is sealed at opposing end caps. The housing at the second endcap 24 closes the open end of the filter, thus preventing air flowtherethrough. Therefore, as shown by arrows 50, the air flows into theinterior of the filter from the first end 6 through the filter area 4and out a side conduit of the housing. A space is created between thefilter and the housing to accommodate the air flow out of the filter andthrough the outlet conduit of the housing. The filter is maintained inthe desired location through the frictional engagement of the end capsto the housing.

The air filters according to the embodiments described herein allow moreair_(,) to pass through the filter while retaining the same filteringcapabilities as conventional filters. This provides for additionalpower, especially at higher rpms.

In an exemplary embodiment, the circular projection of the first end cap22 defining the opening tapers from a diameter of about 6 to 15 inches,and preferably approximately 8 to 10 inches, or 9 inches at its widestpoint to a diameter of about 3 to 12 inches, and preferably 6.5 to 8.5inches, or 7.5 inches at its narrowest point. The narrow circular recessis about ⅓ to 1 inch, or ⅔ of an inch wide and has a diameter of between7 and 13 inches or about 9 to 10.5 inches, r about 9.75 inches (asmeasured from the center of the circular recess). The narrowest portionof the opening of the first end cap 22 is nearly as large in diameter asthe inner diameter of the filter media and inner liner. Accordingly, theinner surface of the first end cap (i.e., between the filter media andthe opening) is very narrow (approximately under about ½ inches, orapproximately about ¼ inch in width).

For the second end cap, the circular projection defining the openingtapers from a diameter of approximately 5 to 10 inches or approximately7 to 8 inches, or about 7.5 inches at its widest point to a diameter ofapproximately 4 to 9 inches, or about 5 to 7 inches, or about 6 inchesat its narrowest point. There is also a small circular ridge of about 6to 7 inches or 6.5 inches in diameter along the taper of the circularprojection. The circular recess is about 1.5 to 3.5 inches wise, orapproximately 2.5 inches wide, has a diameter of about 8 to 12 inches,or approximately 10 inches (as measured from the center of the circularrecess). The circular recess also includes two narrow circular trenchesin the floor of the circular recess with diameters of, for example,about 8.75 inches and 11.5 inches respectively.

The material of the end caps is sufficiently hard to retain the filtermedia in the desired configured and support the filter when coupled tothe filter housing. The material is also durable enough for repeatedcleaning and use. However, the material provides some flexibility orgive so that a frictional engagement may be achieved between the filterand the inserted pipe. The material therefore compresses when a matingsurface of the filter housing contacts, abuts, or is inserted intocontours of the filter end caps such that a sealed engagement isachieved between the housing and filter. The open end cap, integratedinto the filter, therefore creates the attachment mechanism for thefilter to the housing, the sealing mechanism, as well as the support forthe filter media.

Embodiments as described herein are very robust, which means they areincredibly easy to clean. The filters may be cleaned with or without adegreasing agent, and pressure washed, compress air blown, or watersprayed to remove the built up particulate, including dirt and grimefrom the filter material. The potential reuse of the filter reduces thecost of replacing air filters. The depth-loading of the filter materialmay be washable. Because of the fitted end caps, the air filter isremovable from the housing to permit replacement, servicing, andcleaning of the filter. Moreover, when restriction builds beyond adesired level, the filter may simply be washed. So instead of shortcycling expensive disposable air filters, embodiments according to thepresent description keep restriction down and horsepower up.

It will be understood that the terms “top,” “side,” and “bottom” usedherein are intended to provide a frame of reference for purposes ofdescribing embodiments of the air filter. The actual orientation of theair filter in use and the direction of air flow may vary. In additional,the recitations to a first, second, or more components is intended notto require a specific number or location of a specific component, butmerely used as a distinguishing reference from one component to another.Moreover, and feature of the present configuration may be duplicated,removed, moved, reconfigured in any combination with respect to anyother feature, such that the exemplary embodiment including all of thedescribed features and positions are not necessary.

Although embodiments of this invention have been fully described withreference to the accompanying drawings, it is to be noted that variouschanges and modifications will become apparent to those skilled in theart. Such changes and modifications are to be understood as beingincluded within the scope of embodiments of this invention as defined bythe appended claims.

Thus, specific embodiments and applications of air filters have beendisclosed. It should be apparent, however, to those skilled in the artthat many more modifications besides those already described arepossible without departing from the inventive concepts herein. Theinventive subject matter, therefore, is not to be restricted except inthe spirit of the appended claims. Moreover, in interpreting both thespecification and the claims, all terms should be interpreted in thebroadest possible manner consistent with the context. In particular, theterms “comprises” and “comprising” should be interpreted as referring toelements, components, or steps in a non-exclusive manner, indicatingthat the referenced elements, components, or steps may be present, orutilized, or combined with other elements, components, or steps that arenot expressly referenced. Where the specification claims refers to atleast one of something selected from the group consisting of A, B, C, .. . and N, the text should be interpreted as requiring only one elementfrom the group, not A plus N, or B plus N, etc.

We claim:
 1. An air filter, comprising: a first end cap at a firstterminal end of the air filter, the first end cap having a firstopening; a second end cap at a second terminal end of the air filteropposite the first terminal end, the second end cap having a secondopening; and a filter media coupled to and sealed between the first endand the second end to circumferentially surround an interior cavity. 2.The air filter of claim 1, comprising a rim defining the first openingand extending longitudinally past an exterior terminal end of the firstend cap.
 3. The air filter of claim 2, wherein an interior surface ofthe rim defining the first opening is tapered such that an interiordiameter at a terminal edge of the end cap away from the filter media isgreater than an interior diameter along the interior surface away fromthe terminal edge.
 4. The air filter of claim 3, wherein the taperedinterior surface is accurate.
 5. The air filter of claim 2, furthercomprising a flange circumferentially surrounding a longitudinal portionof the rim extending longitudinally past a terminal end of an exteriorperimeter of the first end cap.
 6. The air filter of claim 5, whereinthe flange projects radially inwardly.
 7. The air filter of claim 1,wherein the second end cap comprises an interior rim defining the secondopening and projecting longitudinally outwardly from an terminal end ofa portion of the second end cap.
 8. The air filter of claim 7, whereinthe second end cap comprises an exterior rim defining an exteriorperimeter of the second end projecting longitudinally outward from theterminal end of the portion of the second end cap, such that a radialgap separates the interior rim from the exterior rim.
 9. The air filterof claim 8, wherein an interior surface of the interior rim comprises acircumferential ridge around the first opening.
 10. The air filter ofclaim 8, wherein a material of the first end is configured to deformwhen mated with a filter housing.
 11. That air filter of claim 8,wherein a material of the second end is configured to deform when matedwith a filter housing.